1. Field of the Invention
The invention relates to lubricant compositions. More particularly, it relates to a group of etherdiamine borates and to their use in lubricants as multipurpose additives, i.e., as rust, friction, antioxidant and fuel consumption reducers. The invention is especially concerned with lubricating internal combustion engines.
2. Discussion of Related Art
As those skilled in this art know, additives impart special properties to lubricants. They may give the lubricants new properties or they may enhance properties already present. One property all lubricants must have is the reduction of rust on lubricated parts in contact.
Borated amides, borated alkanolamines, borated ureas, amine salts of boron acids, chlorinated amine-boron complexes and aromatic amine-boron mixtures have been used in the past as described in U.S. Pat. Nos. 3,449,362, 3,254,025, 2,999,064, 4,226,734, 3,076,835, 4,025,446, 3,014,870, 3,014,869 and 3,007,873. Related borated adducts of alkylamines and alkyldiamines are disclosed as lubricant friction reducers in U.S. Pat. No. 4,328,113. The alkyldiamine borates disclosed in U.S. Pat. No. 4,328,113 do not, however, possess significant antirust properties. The etherdiamine borates disclosed herein have been compared with alkyldiamine borates and found to possess far superior antirust properties. As a result, our etherdiamine borates described herein provide substantial antirust, friction reducing, oxidative and high temperature stability advantages unavailable in any of the prior art disclosures.